need help identifying a house light lamp

[clopedia89]

I volunteer in a high school theater, and we're having an issue with the bulb life of our house lights. A portion of our house lights are made up of 500W halogen lamps, of which 5 are extremely difficult to get to for lamp changes. Around 15-20 years ago, the maintenance guy at the time (since retired) got tired of dealing with them and managed to find some lamps that were "guaranteed to last decades." He managed to convince the school to pay the higher price for these lamps, and they have indeed lasted a ridiculously long time. All 5 lasted at least 15 years of daily use (some are getting close to 20 years now), but have sadly begun to die. We have been changing them out with the same lamp we use for the other, more accessible, fixtures of the same type, but the life span, while fairly typical for this lamp, is short enough to be causing some major headaches for our maintenance team. Our question is simple: Can anyone look at these pictures and identify the old bulb that lasted 15+ years and tell us where to get more?

The lamps in the pictures are arranged as follows, left to right:
- 120v lamps we are currently using
- 500QCLMC 130v lamps we are switching to in an attempt to extend bulb life
- old, unknown lamp with 15+ year lifespan

(Also, our supply voltage never exceeds 118v as measured by our dimmer rack, and almost always sits around 113v-117v, so i doubt rated voltage is an issue.)

 

[RonHebbard]

I volunteer in a high school theater, and we're having an issue with the bulb life of our house lights. A portion of our house lights are made up of 500W halogen lamps, of which 5 are extremely difficult to get to for lamp changes. Around 15-20 years ago, the maintenance guy at the time (since retired) got tired of dealing with them and managed to find some lamps that were "guaranteed to last decades." He managed to convince the school to pay the higher price for these lamps, and they have indeed lasted a ridiculously long time. All 5 lasted at least 15 years of daily use (some are getting close to 20 years now), but have sadly begun to die. We have been changing them out with the same lamp we use for the other, more accessible, fixtures of the same type, but the life span, while fairly typical for this lamp, is short enough to be causing some major headaches for our maintenance team. Our question is simple: Can anyone look at these pictures and identify the old bulb that lasted 15+ years and tell us where to get more?

The lamps in the pictures are arranged as follows, left to right:
- 120v lamps we are currently using
- 500QCLMC 130v lamps we are switching to in an attempt to extend bulb life
- old, unknown lamp with 15+ year lifespan

(Also, our supply voltage never exceeds 118v as measured by our dimmer rack, and almost always sits around 113v-117v, so i doubt rated voltage is an issue.)

Calling @DELO72
Toodleo!
Ron Hebbard

 

[ship]

E-11 EVR type lamp. Not the most efficient lamp but see the Colortran Mini Ellipse debate. Not aware of a LED version of this lamp. Not much more than cleaning the fixtures / look at the lamp socket for changing you can do with it I think. Possibly change to a different lamp socket / base type such as G-9.5 or HS G-9.5 but for a school shuch a change would probably be against the rules. Better lamps available and might just bench focus the same.

 

[FMEng]

I run a small flock of those and they are a very good bulb and socket, so I would not change anything. EVR is the lamp code for the 120V, standard life version. The lamp code for the 130V, long life bulb is EYW. In more generic terms, it is a Q500/CL/MC-130V. Q500 means 500 Watt quartz, CL for clear, MC for miniature candelabra screw base, and 130V for the voltage.

The unknown lamp is just a 130V bulb. The higher voltage rating is what makes it "long life." There are no other special properties, except for maybe a good salesman. At low nominal voltages like yours, they'll last way longer than the specs. Keeping them dimmed a little greatly increases life, too. The trade off for long life is a slight reduction in lumen output and a warmer color temperature.

A google search shows them to be widely available. Here's one dealer that has them.
https://www.lightbulbs.com/search/?keywords=eyw

It's interesting to note they carry four different brands, ranging in price from $4.89 to $31.99 The cheapest is rated at 1,700 hours, but the others have a 2,000 hour rating. For a hard to reach place, I wouldn't buy the cheapest.

 

[macsound]

Looks interesting that the filament is shorter within the envelope and seemingly thicker.
If you look at the images from the 4 on the above mentioned lightbulbs.com website, they also differ in length. Not sure if there's a technical reason or simply skirting patents or something.

 

[TheaterEd]

major headaches for our maintenance team.

Maybe this can help!

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[BillConnerFASTC]

Fantastic!

 

[JimP0771]

Maybe this can help!

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Never thought of this Idea perhaps I can use this on all my stage lighting as well. It would be tough though having to open the fixture to get to the lamp.